A number of biodegradable polymeric materials have been adapted for surgical use, and for controlled release of bioactive substances. Polymeric and pre-polymeric materials that may be optionally cross-linked that do not comprise a colorant have been used to prevent post-operative surgical adhesions. Examples of such polymers are set forth below.
U.S. Pat. No. 5,162,430 to Rhee et al., discloses collagen-synthetic polymer conjugates prepared by covalently binding collagen to synthetic hydrophilic polymers such as various derivatives of polyethylene glycol.
U.S. Pat. No. 5,324,775 to Rhee et al., discloses various insert, naturally occurring, biocompatible polymers (such as polysaccharides) covalently bound to synthetic, non-immunogenic, hydrophilic polyethylene glycol polymers.
U.S. Pat. No. 5,328,955 to Rhee et al., discloses various activated forms of polyethylene glycol and various linkages which can be used to produce collagen-synthetic polymer conjugates having a range of physical and chemical properties.
EP 0732109A1 to Rhee, discloses a crosslinked biomaterial composition that is prepared using a hydrophobic crosslinking agent, or a mixture of hydrophilic and hydrophobic crosslinking agents. Preferred hydrophobic crosslinking agents include any hydrophobic polymer that contains, or can be chemically derivatized to contain, two or more succinimidyl groups.
U.S. Pat. No. 5,580,923 to Yeung et al., discloses a composition useful in the prevention of surgical adhesions comprising a substrate material and an anti-adhesion binding agent; where the substrate material preferably comprises collagen and the binding agent preferably comprises at least one tissue-reactive functional group and at least one substrate-reactive functional group.
U.S. Pat. No. 5,614,587 to Rhee et al., discloses bioadhesive compositions comprising collagen crosslinked using a multifunctionally activated synthetic hydrophilic polymer, as well as methods of using such compositions to effect adhesion between a first surface and a second surface, wherein at least one of the first and second surfaces is preferably a native tissue surface.
Japanese Patent Publication No. 2002-088336 to Yokoyama et al. discloses a composition used for temporary adhesion of a lens material to a support, to mount the material on a machining device, comprising a mixture of polyethylene glycol, having an average molecular weight in the range of 1000-5000, and poly-N-vinylpyrrolidone, having an average molecular weight in the range of 30,000-200,000.
West and Hubbell, Biomaterials (1995) 16:1153-1156, disclose the prevention of post-operative adhesions using a photopolymerized polyethylene glycol-co-lactic acid diacrylate hydrogel and a physically crosslinked polyethylene glycol-co-polypropylene glycol hydrogel, POLOXAMER 407®.
A polymeric composition that includes a permanent colorant has also been reported, e.g., WO 00/09087 to Sawhney, which relates to hydrogel biomaterials that may also include a permanent colorant. Such a permanent colorant can be generated in situ or one permanent color may be changed to a different permanent color by a chemical reaction after application of the biomaterial. While such permanently colored biomaterials can be helpful to a surgeon in locating where a composition or prosthesis is located at a surgical site, they can also hinder or obliterate the visibility of tissue to which the colored materials have been applied. During surgical procedures, such colored biomaterials can lessen a surgeon's ability to easily and quickly identify bleeding at a surgical site or may lessen a surgeon's ability to view anatomical structures that may be covered by such biomaterials.
Accordingly, there is a need for improved biocompatible compositions that overcome the difficulties described above, and provide improved visibility during surgical procedures.
Each publication cited above is incorporated herein by reference to describe and to disclose the subject matter for which it is cited.